Projector

ABSTRACT

A projector  10  projects an image onto a set of screens  14  for image formation. The set of screens  14  includes a first screen  50  and second screens  54  and  56 . The projector includes a housing  20 , a first screen fixture  74  and a second screen fixture  76 . The housing  20  has an opening  30  for fitting the first screen  50  therein. The first screen fixture  74  positions the first screen  50  in the housing opening  30  and fixes an inner surface of the first screen  50  adhesively to the housing  20 . The second screen fixture  76  is positioned between the first screen  50  and the first screen fixture  74 , and fixes the second screens  54  and  56  between itself and the inside of the first screen  50.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to improvements in a projector forprojecting an image onto a set of screens for image formation.

2. Description of the Related Art

There is known a projector for projecting an image, a picture or thelike on an enlarged scale onto the backside of relatively large screens.

The projector includes an optical unit including a projection lens forenlarging an image or the like and projecting it onto the screens.

FIGS. 1 and 2 show a structure for fixing the screens of a conventionalprojector 2000.

The projector 2000 includes a contrast screen 2023, a lenticular screen2005 and a fresnel screen (or lens) 2006. The screens 2023, 2005 and2006 are fixed to a screen frame 2003 by means of a screen holder 2012and screws 2013. The screen frame 2003 includes a front part 2020, whichincludes bosses 2028 protruding inward. Each screw 2013 is threaded intoone of the bosses 2028 to fix the screen holder 2012 to the bosses 2028.This fixes the screens 2023, 2005 and 2006 between the inside 2032 ofthe front frame part 2020 and the inside 2034 of the screen holder 2012.

The front frame part 2020 extends along the four sides of the screenframe 2003 and has a width 2040, which is relatively large enough tohide the screen holder 2012, bosses 2028 and screws 2013 from a viewerM.

Consequently, the front part 2020 of the screen frame 2003 restricts theprojector greatly in design.

The screens 2023, 2005 and 2006 may need to be assembled and fixedmanually with the screws 2013 threaded into the screen holder 2012. Themanual fixing work is troublesome, and the assembly productivity is low.

SUMMARY OF THE INVENTION

In view of the foregoing problems, the object of the present inventionis to provide a projector that can be fitted simply with a set ofscreens, and that has no restriction in its front design.

According to a first aspect of the present invention, there is provideda projector for projecting an image onto a set of screens for imageformation. The set of screens includes a first screen and a secondscreen. The projector includes a housing having an opening for fittingthe first screen therein. The projector also includes a first screenfixture for positioning the first screen in the housing opening andfixing an inner surface of the first screen adhesively to the housing.The projector further includes a second screen fixture positionedbetween the first screen and the first screen fixture. The second screenfixture fixes the second screen between itself and the inside of thefirst screen.

Thus, the first screen fixture can fix the first screen in the housingopening adhesively to the housing. The adhesive fixation is very simpleand secure or reliable, and does not need screws or the like.

The second screen fixture is positioned between the first screen and thefirst screen fixture, and simply fixes the second screen between itselfand the inside of the first screen. Accordingly, it is possible to fixthe first and second screens by means of only a pinch and adhesionwithout needing screws, a screen holder, etc. This improves theprojector assembly productivity.

Because the first screen fixture adhesively fixes the inner surface ofthe first screen, it is not necessary to form a portion of the housingon the outside of the first screen to fix this screen. This allows thefirst screen to be large in size to fit the housing opening.

Consequently, it is possible to reduce the restrictions on the design ofthe projector. Because there is no need for members such as screws and ascreen holder, the assembly productivity is improved.

The first screen may be a contrast screen for protecting the secondscreen and for improved contrast in external light.

The second screen may include a fresnel screen and a lenticular screen.The fresnel screen converts projected divergent beams into parallelbeams. The lenticular screen diverges the parallel beams in the rightand left directions.

The first screen fixture may include a fitting structure and a fittingmember. The fitting structure protrudes from the inside of the housing.The fitting member includes a first part and a second part. The firstpart is fixed in engagement with the fitting structure. The second partis fixed adhesively to the inner surface of the first screen. The secondscreen fixture may include a first pinch part and a second pinch part.The first pinch part is connected to the fitting structure. The secondpinch part is provided on the side of the fitting member that isopposite to the first screen.

The second pinch part of the second screen fixture may be the innersurface of the first screen.

According to a second aspect of the present invention, there is provideda projector for projecting an image onto a set of screens for imageformation. The set of screens includes a first screen and a secondscreen. The projector includes a housing having an opening for fittingthe first screen therein. The projector also includes a first screenfixture for positioning the first screen in the housing opening andfixing the first screen into engagement with the housing. The projectorfurther includes a second screen fixture positioned between the firstscreen and the first screen fixture. The second screen fixture fixes thesecond screen between itself and the inside of the first screen.

Thus, the first screen fixture fixes the first screen into engagementwith the housing, while the second screen fixture fixes the secondscreen between itself and the inside of the first screen.

The simple pinching fixation does not need a screen holder or anothermember and screws as used in the prior art. This improves the projectorassembly productivity.

The first screen of this projector may be a contrast screen forprotecting the second screen and for improved contrast in externallight.

The second screen of this projector may include a fresnel screen forconverting projected divergent beams into parallel beams and alenticular screen for diverging the parallel beams in the right and leftdirections.

The first screen fixture of this projector may include a fittingstructure and a fitting member. The fitting structure protrudes from theinside of the housing. The fitting member includes a first part and asecond part. The first part is fixed in engagement with the fittingstructure. The second part protrudes from the inside of the firstscreen. The second screen fixture may include a first pinch part and aninner surface of the first screen. The first pinch part is connected tothe fitting structure.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred form of the present invention is illustrated in theaccompanying drawings in which:

FIG. 1 is a cross section showing a structure for fitting the screens ofa conventional projector;

FIG. 2 is a perspective view showing the structure of FIG. 1;

FIG. 3 is a perspective view of a projector according to a preferredembodiment of the present invention;

FIG. 4 is an exploded perspective view of the projector of FIG. 3,showing the screens and housing of the projector;

FIG. 5 is a cross section along line A-A of FIG. 3;

FIG. 6 is a cross section along one of lines B-B of FIG. 3, showing howthe screens are fitted;

FIG. 7 is a perspective view of a fitting member and a fitting structurefor fitting the contrast screen of the projector of FIGS. 3-5;

FIG. 8 is a cross section showing another embodiment of the presentinvention;

FIG. 9 is a cross section showing still another embodiment of thepresent invention;

FIG. 10 is a cross section showing yet another embodiment of the presentinvention;

FIG. 11 is a cross section showing a further embodiment of the presentinvention; and

FIG. 12 is a cross section showing a still further embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention are described below indetail with reference to the accompanying drawings. Although theembodiments have technically preferred limitations, the scope of theinvention is not limited to the embodiments unless it is stated hereinthat the invention is limited to any of them.

With reference to FIGS. 3 and 4, a projector 10 projects and displays animage or the like on the inside of a set of screens 14, which a viewer Mcan view.

With reference to FIG. 5, the projector 10 includes a housing 20, whichhouses a reflecting mirror 24 and an optical unit 26. The optical unit26 may include an LCD panel.

The image projected by the optical unit 26 is reflected by thereflecting mirror 24 and projected on the inside of the set of screens14. The viewer M can view the projected image through the set of screens14. A projector of such structure may be referred to as a rearprojection television receiver.

With reference to FIG. 4, the housing 20 has an opening 30, which may berectangular, and includes a frame 40. For the formation of the projectedimage, the set of screens 14 is fitted in the opening 30 and fixed tothe frame 40. The frame 40 should preferably have an upper side, a lowerside, a right side and a left side around the opening 30.

The set of screens 14 consists of a first screen that is a contrastscreen 50 and two second screens that are a lenticular screen 54 and afresnel screen (or lens) 56. The contrast screen 50 and fresnel screen56 are positioned on the outside and inside respectively of thelenticular screen 54.

With reference to FIGS. 4 and 6, the contrast screen 50 is a front plateprovided for improved contrast in external light, and for protection ofthe surfaces of the lenticular screen 54 etc., which face the viewer M.

The fresnel screen 56 may be formed of acryl, polycarbonate or othermaterial. The fresnel screen 56 serves to make parallel the divergentbeams of the image projected by the optical unit 26, which is shown inFIG. 5.

The lenticular screen 54 may be formed of acryl, polycarbonate or othermaterial. The lenticular screen 54 serves to diverge the parallel beamsin the right and left directions.

As shown in FIG. 6, the screens 50, 54 and 56 are fixed to the frame 40by fixing structures 70.

With reference to FIG. 6, the frame 40 does not include a wide frontportion as is included in the prior art, but the viewer M can see thefront end 60 of the frame 40, which has a thickness T. Thus, therectangular opening 30, which is surrounded by the front end 60 of theframe 40, is smaller than the outer size of the frame 40 by thethickness T, but is very large in design.

The opening 30 is filled substantially with the contrast screen 50.Preferably, the front side 31 of this screen 50 should be substantiallyflush with the front end 60 of the frame 40.

As shown in FIG. 6, each fixing structure 70 consists of a first screenfixture 74 and a second screen fixture 76.

With the contrast screen 50 positioned in the opening 30, the firstscreen fixtures 74 of the fixing structures 70 fix the inside 33 of thisscreen 50 with adhesive means 78 to the housing 20.

Specifically, each first screen fixture 74 includes a fitting structure80 and a fitting member 84.

The fitting structure 80 protrudes in parallel with the contrast screen50 from the inside 88 of the frame 40. The fitting structure 80 includesa vertical part 80A and protrusions 100. The vertical part 80A has holes90 formed through it, each of which is adjacent to one of theprotrusions 100.

As shown in FIG. 6, the fitting member 84 is substantially L-shaped insection. As shown in FIGS. 6 and 7, the fitting member 84 includeshorizontal parts 96 and a vertical part 98. As shown in FIG. 6, eachhorizontal part 96 extends through one of the holes 90 of the fittingstructure 80. Each horizontal part 96 has a hole 102 formed through it,which engages with one of the protrusions 100 of the fitting structure80. The fitting member 84 could alternatively be T-shaped in section.

The fitting member 84 is positioned near an edge of the contrast screen50. The vertical part 98 of this member 84 is fixed to the inside 33 ofthis screen 50 adhesively by one of the adhesive means 78.

As shown in FIG. 7, the vertical part 98 of the fitting member 84 takesthe form of a belt longer than the horizontal parts 96. The horizontalparts 96, which may be two in number, extend perpendicularly to thevertical part 98.

Thus, the contrast screen 50 is fixed to the housing frame 40 by thefitting structures 80 and the fitting members 84 of the first screenfixtures 74 and adhesively by the adhesive means 78. This removes theneed for screws, metallic screen holders for fitting, and other membersas conventionally used. It is consequently possible to fix the contrastscreen 50 by means of engagement without screws, thereby greatlyimproving the assembly productivity.

The contrast screen 50 can substantially fill the opening 30 andaccordingly be positioned within the front end 60 of the frame 40. Thismakes it possible to enlarge the contrast screen 50 in area as comparedwith the prior art. In other words, it is possible to minimize thedimension A. (FIG. 6) between an outer surface of the housing 20 and theinner edge of the adjacent adhesive means 78, making the housing 20compact. The inner edges of all adhesive means 78 are positionedslightly outside the effective size of the contrast screen 50.

The adhesive means 78 may be double-coated tape, or a liquid, fluid orsolid adhesive.

It is thus possible to fix the contrast screen 50 substantially flush inthe frame opening 30 simply and securely by means of engagement andsimple adhesion.

The second screen fixtures 76 of the fixing structures 70 fix thelenticular screen 54 and fresnel screen 56 extending on each other onthe inside of the contrast screen 50. Each second screen fixture 76consists of a pinch surface 110 of the vertical part 98 of theassociated fitting member 84 and a pinch member 114. The pinch member114 is integral with the associated fitting structure 80 and positionednear the holes 90. The pinch member 114 and pinch surface 110 face eachother, and the screens 54 and 56 are held between them.

The thus held lenticular screen 54 and fresnel screen 56 are spacedslightly from the inside 33 of the contrast screen 50 and positioned inparallel to this screen 50.

FIGS. 8-11 show other embodiments of the present invention.

FIGS. 8-11 are similar to FIG. 6, and similar parts in them are assignedthe same reference numerals to avoid repeated description.

The embodiment of FIG. 8 differs from that of FIG. 6 in the followingpoints.

Although the fitting structures 80 of the first screen fixtures 74 areidentical, the fitting members 84 of the first screen fixtures 74 areslightly different. The fitting members 84 in FIG. 8 are generallyT-shaped in section, and each include horizontal parts 96 and a verticalpart 98. Each horizontal part 96 has a hole 102 formed through it. Thevertical part 98 is fixed with an adhesive means 78 to the inside 33 ofthe contrast screen 50. The fitting structure 80 has holes 90 formedthrough it, and each horizontal part 96 extends through one of the holes90.

The sectionally T-shaped fitting members 84 could alternatively beL-shaped in section. The sectionally L-shaped fitting members of otherembodiments could alternatively be T-shaped in section.

Each second screen fixture 76 in FIG. 8 consists of a pinch member 114and the inside 33 of the contrast screen 50, which pinch the lenticularscreen 54 and fresnel screen 56 between them. The lenticular screen 54and fresnel screen 56 extend on each other closely on the inside of thecontrast screen 50.

The embodiment of FIG. 9 differs from that of FIG. 6 in the followingpoints.

Although the fitting structure 80 of each first screen fixture 74 inFIG. 9 includes a vertical part 80A and has holes 90 formed through it,it does not include protrusions 100 as shown in FIG. 6. The fittingmembers 84 of the first screen fixtures 74 are generally L-shaped insection. Each horizontal part 96 of the fitting member 84 extendsthrough one of the holes 90 and is fixed on the inside of the fittingstructure 80 by a stopper 130. The vertical part 98 of the fittingmember 84 is fixed to the inside 33 of the contrast screen 50 adhesivelyby an adhesive means 78.

Each second screen fixture 76 in FIG. 9 consists of a pinch member 114and a pinch surface 110 of the vertical part 98 of the fitting member84. The lenticular screen 54 and fresnel screen 56 extending on eachother are fixed between the pinch member 114 and pinch surface 110, andspaced from the inside 33 of the contrast screen 50.

In the embodiment shown in FIG. 10, each first screen fixture 74includes a fitting structure 80 extending integrally from an innersurface 88 of the frame 40. The fitting structure 80 functions also as afitting member (84 in FIG. 6). The outside of the fitting structure 80is fixed to the inside 33 of the contrast screen 50 adhesively by anadhesive means 78.

Each second screen fixture 76 of this embodiment consists of a pinchmember 114 and the inside 33 of the contrast screen 50, between whichthe lenticular screen 54 and fresnel screen 56 are fixed. This makes thelenticular screen 54 extend closely between the contrast screen 50 andfresnel screen 56.

In the embodiment shown in FIG. 11, each first screen fixture 74includes a fitting structure 80 and a fitting member 84. The fittingstructure 80 has holes 90 formed through it. The fitting member 84includes horizontal parts 96 and a vertical part 98. Each horizontalpart 96 extends through one of the holes 90 and includes a pawl 140. Thevertical part 98 is fixed to the inside 33 of the contrast screen 50adhesively by an adhesive means 78. The fitting structure 80 includespawls 146 each engaging with one of the pawls 140. Thus, the fittingmembers 84 fix the contrast screen 50 to the frame 40.

Each second screen fixture 76 in FIG. 11 consists of a pinch member 114and a pinch surface 110 of the vertical part 98 of the fitting member84, between which the lenticular screen 54 and fresnel screen 56 arefixed. This spaces the lenticular screen 54 and fresnel screen 56 fromthe inside 33 of the contrast screen 50.

FIG. 12 shows another embodiment of the present invention.

In FIGS. 6 and 12, similar parts are assigned the same referencenumerals to avoid repeated description.

In FIG. 12, each fixing structure 70 includes a first screen fixture 74for fixing the contrast screen 50 in the opening 30 of the housing 20.

The first screen fixture 74 includes a fitting structure 280 andhorizontal fitting parts 284. The fitting structure 280 includes avertical part 280A extending from the inside of the housing frame 40 andin parallel to the contrast screen 50. The fitting structure 280 hasholes 290 formed through it. Each fitting part 284 extends through oneof the holes 290.

Each fitting part 284 has a hole 302 formed through it. The fittingstructure 280 includes protrusions 300, each of which engages with oneof the holes 302 of the fitting parts 284.

This embodiment is characterized by the fitting parts 284 extendingdirectly from the inside 33 of the contrast screen 50 inward of thehousing 20 and in parallel to the frame 40. The fitting parts 284 areintegral with the contrast screen 50, which is fixed by the fittingstructures 280 and parts 284 of the first screen fixtures 74 by means ofengagement without an adhesive. The fitting parts 284 couldalternatively not be parallel to the frame 40.

Each second screen fixture 76 of this embodiment consists of a pinchmember 314, which is integral with the associated fitting structure 280,and the inside 33 of the contrast screen 50. The lenticular screen 54and fresnel screen 56 are fixed between the inside 33 of the contrastscreen 50 and the pinch member 314. Accordingly, the three screens 50,54 and 56 are positioned closely in parallel.

In each embodiment, as described above, it is possible to fix the threescreens 50, 54 and 56 in the opening 30 of the housing 20 simply andsecurely without specially providing metal parts, such as screws and ascreen holder, and threading the screws. This greatly improves theassembly productivity of the screens.

Because there is no need for screws and a screen holder, it is possibleto reduce the number of parts.

As shown in FIG. 6, for example, the four sides of the contrast screen50 can be adjacent to the front end 60 of the frame 40. This enables thecontrast screen 50 to substantially fill the opening 30 of the frame 40.In other words, it is possible to minimize the dimension A (FIG. 6) incomparison with the prior art. Because the contrast screen 50 istransparent, its portions for the dimension A need to be colored byprinting or the like so as to hide the adhesive means 78, first screenfixture 74 and second screen fixture 76. Because the dimension A can besmall, the printed area of the contrast screen 50 can be small. It isaccordingly possible to fix the contrast screen 50 etc. without using afront frame part as included in the housing of the prior art. Thisreduces the restrictions on the design of the projector.

The present invention is not limited to the foregoing embodiments.

In each embodiment, the screen fixing structures may be provided at notonly the top and the bottom but also the right and left sides of thehousing frame. The first and second screen fixtures may be provided atonly the top and the bottom or only the right and left sides of thehousing frame.

As described hereinbefore, the present invention is a projector that canbe fitted simply with screens, and that has no restriction in its frontdesign.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description and all changeswhich come within the meaning and range of equivalency of the claims aretherefore intended to be embraced therein.

1. A projector for projecting an image onto a set of screens for imageformation, the set of screens including a first screen and a secondscreen, the projector comprising: a housing having an opening forfitting the first screen therein; a first screen fixture for positioningthe first screen in the housing opening and fixing an inner surface ofthe first screen adhesively to the housing, said adhesive connectionbetween said first screen and said housing being the sole means forfixing said screen to the housing, the first screen fixture comprises afitting structure and a fitting member, the fitting structure protrudingfrom inside of the housing, the fitting member including a first partand a second part the first part fixed in engagement with the fittingstructure, the second part fixed adhesively to the inner surface of thefirst screen; and a second screen fixture positioned behind the firstscreen and the first screen fixture and having a portion thereof heldwithin an opening in said first screen fixture for fixing the secondscreen between the second screen fixture and the inside of the firstscreen, the second screen fixture comprises a first pinch part and asecond pinch part, the first pinch part connected to the fittingstructure, the second pinch part provided on the side of the fittingmember that is opposite to the first screen; wherein said first screenis larger than said second screen.
 2. A projector according to claim 1,wherein the first screen is a contrast screen for protecting the secondscreen and for improved contrast in external light.
 3. A projectoraccording to claim 2, wherein the second screen comprises: a fresnelscreen for converting projected divergent beams into parallel beams anda lenticular screen for diverging the parallel beams in the right andleft directions. 4-9. (canceled)